'This one is Israeli acid-folk-psych. I saw it in a charity shop and thought, there's no way I'm leaving that' ... Gareth Goddard with his collection. Photograph: Sarah Lee

In his east London flat, Gareth Goddard is communing with his record collection. Actually, it's a mere sliver of his total hoard; he has selected 50 of his strangest, rarest acquisitions for our meeting. He holds up a sleeve depicting a grinning, bespectacled hippie lounging under a tree. All the writing is in Hebrew. "This is one of my ultimate discoveries," he beams. "Israeli acid-folk-psych. It's bananas. I saw it in a charity shop and thought, there's no way I'm leaving something like that." Next up is an album by a forgotten glam-rock band. "One of the guys emailed me out of the blue saying the last time he saw the lead singer he'd written 'I can't take anymore' in blood on the hotel mirror and just disappeared." He shakes his head in amazement.

Under the name Cherrystones, Goddard curates compilations for official release - but it is not so much a job as a calling. He's been collecting since he was eight. Watching him leaf through his records, I feel like I'm being shown around the vaults of a museum.

We music lovers live in a time of plenty that has made us lazy. Anybody with a credit card and a broadband connection can accumulate a dizzying array of once-exotic music without leaving the house: cut-price reissues from Amazon, downloads from iTunes and out-of-print vinyl from eBay. Because we can obtain music more easily than ever before, we value it less. In January, researchers at the University of Leicester found that music-buyers were becoming apathetic. "The accessibility of music has meant it is taken for granted and does not require a deep emotional commitment once associated with music appreciation," said study coordinator Dr Adrian North.

In the face of this depressing trend stand a small band of devotees who put vast amounts of time and effort into rediscovering those unrecognised records that aren't just a mouse-click away. Some call themselves diggers. An abbreviation of crate digger, the hip-hop term for a vinyl hunter, it has apt associations. Some have made a profession of their hobby. Many of the best British compilations and reissues of recent years are the work of just a few people, including Goddard, Bob Stanley, Andy Votel, Jonny Trunk, John Stapleton, soundtrack composer David Holmes and journalists Jon Savage and Daryl Easlea. The first example of a digger compilation was 1972's Nuggets, on which Jac Holzman and Lenny Kaye marshalled 27 examples of garage rock and psychedelia, ranging from top 20 hits to previously ignored one-offs found in discount bins. Around the same time, British journalist and DJ Dave Godin was championing unsung soul gems, which he divided into "deep soul" and "northern soul" and compiled for the Kent label. In both cases, knowledgeable enthusiasts retrospectively defined whole genres.

When hip-hop embraced sampling in the late 1980s, it prompted a slew of so-called "breaks and beats" bootleg albums that featured the original records appropriated by hip-hop producers. Jean-Jacques Perrey's 1960s Moog oddity EVA took this path out of oblivion: sampled on a Gang Starr track, widely bootlegged, officially compiled and eventually employed to flog Lucozade. Now that hip-hop relies less on samples, the job of introducing obscurities back into pop's bloodstream falls to a new wave of diggers.

Some do it purely for pleasure. The online home of amateur diggers is Vinyl Vulture. Founded six years ago by two chemistry PhDs called Simon Watson and Chris Malins, it brings together some of the most passionate and well-informed music aficionados in the country; Andy Votel and John Stapleton are among the forum's regular contributors. A year ago, Vinyl Vulture instituted a regular CD swap. Each of the 60 people currently signed up has to burn a compilation of rare tracks that, to the best of their knowledge, have neither been reissued nor officially compiled. They then make 60 copies and mail them to Watson before the deadline; a few days later 60 different CDs of lovingly collated music arrive in the post. It's an extension of making compilation tapes for your friends; the whole point is to introduce people to music they have never heard before. "The rule is basically this: no secret squirrels," says Watson. "If you put something on that CD you're giving it up for the love of the music."

Diggers firmly distance themselves from the kind of collector who hoards rare vinyl. "It can become pretty much stocks and shares, and that element annoys me," says Goddard. "It annoys me that things I know are good are stashed away like little eggs waiting to hatch and not given circulation. Are you collecting music or collecting money?"

The cash-rich, time-poor music fan who regularly buys a batch of CDs has been dubbed Fifty Quid Man. The digger, conversely, might be termed Fifty Pee Man. He (it is invariably he) will spend hundreds of hours a year scouring charity shops, second-hand record stores and car-boot fairs to find records that have languished, unappreciated, for years.

Every digger I speak to regards eBay as a guilty pleasure at best, fostering greed among sellers and laziness among buyers. For over a decade, Simon Watson has been hunting for an original copy of Moody's Gentle Rain, an absurdly rare easy listening record from 1973. He doggedly refuses to spend £200 to buy one online. "I want to find it in the wild," he says. "It's become such a rat race buying online. All the mystery's gone."

He thinks digital music is even less fulfilling. "It's really important for music to have mystique. It's great that everyone can download things but you have memories and attachments to music. It's like the way you make tea. I never make a cup of tea with a teabag; it drives me nuts. I love the idea of making tea with leaves and a strainer. It's related in some way."

Vinyl collecting on this level is a celebration of the clunky and tactile as opposed to the sleek and ephemeral. Chris Malins, who won't even have CDs in the house, sees it as part of a wider response to modern life. "The binary digits that compose the music in its iPod form don't have any value. It's the disposable world of today versus the manufacturing world of yesterday. The analogue culture is very warm and the digital world is very cold and throwaway." The motto of Jonny Trunk's website is: "Retro culture in the information age."

Rescuing records from the bargain bin of history can have heartwarming consequences. Goddard found a record by French funk-rockers Dynastie Crisis in a second-hand shop and included the track Faust 72 on his Hidden Charms compilation. David Holmes then chose it for his soundtrack to Ocean's Twelve and received an email from a member of Dynastie Crisis, astonished and delighted that anyone was interested in something he did over 30 years ago.

But there can be ambivalence too. Only a decade ago, folk singer Vashti Bunyan was a lost enigma whose much-loved sole release, 1970's Just Another Diamond Day, circulated on either third-generation copies or eye-poppingly expensive original vinyl. Now that she has resurfaced and recorded a follow-up, she is finally getting her dues. Unfortunately for her long-time admirers, Just Another Diamond Day's title track can currently be heard advertising T-Mobile.

"When you're putting these things out into the world and the end result is that Vashti Bunyan's on a T-Mobile advert you think, I wish I hadn't done that now," says Stanley. "You do want people to think the album's fantastic but . . ." He trails off, his face a muddle of mixed feelings.

Thus are the borders of obscurity constantly redrawn. Take Nick Drake: a once-arcane cult figure who is now so established in the canon that even James Blunt names him as an influence. With every rediscovery, the diggers have to delve deeper. But the reserves of great, unexplored music seem inexhaustible and that awareness can weigh heavily on a digger. When your enthusiasm and knowledge is this broad, even a lifetime isn't long enough to listen to everything. Chris Malins keeps a list of records he wants to hear and it never gets any shorter. "It's sheer compulsive obsession," he laughs. "Why do we do this? It has to be mental illness of some shape or form. It doesn't lend well to living an ordinary life because it's not the sort of thing you can discuss with ordinary people."

"I dread the day that I die," Gareth Goddard says solemnly, "because I think, 'What the hell's going to happen to my collection?'"